Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
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CENTRIFUGAL FILTER
BACKGROUND OF TILE INVENTION
Cross Reference to Related Applications
This is a non-provisional patent application based upon U.S. Provisional
Patent
Application Serial No. 60/108,830, entitled "ELECTRIC MOTOR DRIVEN
CENTRIFUGAL FILTER", filed November 18, 1998; and is also a continuation-in-
part of
U.S. Patent Application Serial No. 09/176,689, entitled CENTRIFUGAL FILTER AND
METHOD OF OPERATING SAME, filed October 21, 1998, which is a non-provisional
patent application based upon U.S. Provisional Patent Application Serial No.
60/101,804,
entitled "AUXILIARY POWERED CENTRIFUGAL FILTER", filed September 25, 1998.
1. Field of the invention.
The present invention relates to centrifugal filters for filtering
particulates from a
liquid using centrifugal force.
2. Description of the related art.
Many types of fluids contain particulates which need to be filtered out for
subsequent
use of the fluid. Examples of such fluids include medical and biological
fluids, machining
and cutting fluids, and lubricating oils. With particular reference to an
internal combustion
engine, a lubricating oil such as engine oil may contain particulates which
are filtered out to
prevent mechanical or corrosive wear of the engine.
Diesel engine mechanical wear, especially that relating to boundary lubricated
wear, is
a direct function of the amount of particulates in the lubricating oil. A
particulate which is
extremely detrimental to engine wear is soot, formed during the combustion
process, and
deposited into the crankcase through combustion gas blow-by and piston rings
scraping of the
cylinder walls. Soot is a carbonaceous polycyclic hydrocarbon which has
extremely high
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surface area whereby it interacts chemically with adsorptive association with
other lubricant
species. Particle sizes of most diesel engine lubricant soot is between 100
Angstroms and 3
microns. Ranges of concentration are between 0 and 10 percent by weight
depending on
many factors. Because engine wear will dramatically increase with the soot
level in the
lubricating oil, engine manufacturers specify a certain engine drain oil
interval to protect the
engine from this type of mechanical wear. Current sieve type filters do not
remove sufficient
amounts of soot to provide soot related wear protection to the engine.
Centrifugal filters for lubricant filtration are generally known. Current
production
centrifugal lubricant oil filters are powered by hero turbines, which are part
of the oil filter
canister, or through direct mechanical propulsion. Hero turbine powered
filters are limited by
the supplied oil pressure from the engine, and only can operate up to maximum
speeds around
4000 revolutions per minute (RPM) with oil pressures nominally at less than 40
psi. In
addition, hero turbine powered filters pass oil through the filter canister as
it migrates toward
the attached hero turbine jets. Therefore, the lubricant mean residence time
is less than a few
minutes. None of the currently available centrifi~gal filters which operate on
the basis of a
hero turbine provide satisfactory soot removal rates. Soot removal from engine
lubricating
oil requires greater G forces and longer residence times than is demonstrated
with currently
commercially available hero turbine powered filters.
It is also known to drive a centrifugal filter using a mechanical linkage from
a turbine.
The turbine receives a flow of engine exhaust air and drives a mechanical
output shaft which
in turn is coupled with a filter inside a centrifugal filter assembly. The
rotational speed of the
filter is sui~icient to separate particulates within the engine oil. An
example of such a filter is
disclosed in U.S. Patent No. 5,779,618 (Onodera, et al.).
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All of the units described above and others commercially available fall
generally in
groups of hero turbine design or direct mechanical actuation. While direct
mechanically
driven systems are capable of reaching the necessary G forces to provide soot
removal, this
type of linkage is generally very expensive and requires extensive
modification of engines to
adapt. While hero turbines do not suffer from this problem, insui~icient G
forces limit these
filters from removing soot.
SUMMARY OF THE INVENTION
The present invention provides a centrifizgal filter assembly which is driven
by a
brushless direct current motor and includes a venturi section.
The invention comprises, in one form thereof, a centrifi~gal filter assembly
for
filtering particulates from engine oil. A housing includes a threaded
connector. A filter
disposed within the housing is rotatable relative to the housing about an axis
of rotation. The
filter has an inlet and an outlet for the oil. A filter head includes a mating
threaded connector
configured to mate with the housing threaded connector. The filter head
includes a venturi
section in communication with the outlet. The venturi section is configured to
create a
vacuum within the housing for drawing oil through the outlet. A brushless
direct current
motor carned by the filter head has a rotatable output shaft coupled with the
filter for rotating
the filter about the axis of rotation. A controller carried by the filter head
controls operation
of the motor. The controller includes a printed circuit board disposed within
the filter head
which carries the motor.
An advantage of the present invention is that the rotating filter is driven by
the
brushless DC motor at a speed which is sufficient to filter soot from the
engine oil.
Another advantage is that the filter head includes a venturi section which
generates a
vacuum within the housing to remove filtered oil from the housing.
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Yet another advantage is that the motor may be carried by a printed circuit
board
within the filter head, thereby reducing the size of the filter assembly.
Still another advantage is that the filter may be detachably engaged by the
motor in the
filter head, thereby allowing the filter to be used as a spin-on filter.
S A still further advantage is that the housing includes two annular seals
with an annular
groove therebetween which is in communication with a drain tube, thereby
further enabling
use as a spin-on filter.
BRIEF DESCRIPTION OF TFIE DRAWINGS
The above-mentioned and other features and advantages of this invention, and
the
manner of attaining them, will become more apparent and the invention will be
better
understood by reference to the following description of embodiments of the
invention taken
in conjunction with the accompanying drawings, wherein:
Fig. 1 is a perspective, sectional view of an embodiment of a centrifugal
filter
assembly of the present invention;
Fig. 2 is a side, sectional view of another embodiment of a centrifugal filter
assembly
of the present invention;
Fig. 3 is a sectional view taken along line 3-3 in Fig. 2;
Fig. 4 is a fragmentary, side view of still another embodiment of a
centrifi~gal filter
assembly of the present invention;
Fig. 5 is a fragmentary, side view of another embodiment of a centrifugal
filter
assembly of the present invention;
Fig. 6 is a perspective view of an embodiment of a filter of the present
invention;
Fig. 7 is a simplified, side view of still another embodiment of a centrifugal
filter
assembly of the present invention;
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Fig. 8 is a perspective view of an embodiment of a turbine for use with the
centrifugal
filter assembly of the present invention;
Fig. 9 is a perspective view of another embodiment of a turbine for use with
the
centrifugal filter assembly of the present invention;
5 Fig. 10 is a perspective view of yet another embodiment of a turbine for use
with the
centrifugal filter assembly of the present invention;
Fig. 11 is a perspective view of still another embodiment of a turbine for use
with the
centrifugal filter assembly of the present invention;
Fig. 12 is a perspective view of a further embodiment of a variable geometry
turbine
for use with the centrifugal filter assembly of the present invention;
Fig. 13 is a perspective view of yet another embodiment of a turbine for use
with the
centrifugal filter assembly of the present invention;
Fig. 14 is a side sectional view of another embodiment of a centrifugal filter
assembly
of the present invention;
Fig. 15 is an exploded, perspective view of the filter head of Fig. 14;
Fig. 16 is an exploded, partially sectioned view of the centrifugal filter
assembly of
Figs. 14 and 15;
Fig. 17 is a side, sectional view of another embodiment of a centrifi~gal
filter assembly
of the present invention;
Fig. 18 is a side, sectional view of another embodiment of a centrifugal
filter assembly
of the present invention;
Fig. 19 is a side, sectional view of another embodiment of a centrifugal
filter assembly
of the present invention;
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Fig. 20 is a side, sectional view of another embodiment of a centrifugal
filter assembly
of the present invention;
Fig. 21 is a side view of another embodiment of a filter head used with a
centrifugal
filter assembly of the present invention;
Fig. 22 is a side view of a portion of a filter head used in another
embodiment of a
centrifugal filter assembly of the present invention;
Fig. 23 is a perspective, partially fragmentary view of another embodiment of
a
centrifugal filter assembly of the present invention;
Fig. 24 is a perspective, partially fragmentary view of another embodiment of
a
centrifugal filter assembly of the present invention;
Figs. 25 and 26 illustrate an embodiment of a gear box which may be used with
an
internal combustion engine to provide power to a centrifugal filter assembly
of the present
invention;
Fig. 27 is a perspective, partially fragmentary view of another embodiment of
a
centrifizgal filter assembly of the present invention; and
Fig. 28 is a side, sectional view of another embodiment of a centrifizgal
filter assembly
of the present invention.
Corresponding reference characters indicate corresponding parts throughout the
several views. The exemplifications set out herein illustrate one preferred
embodiment of the
invention, in one form, and such exemplifications are not to be construed as
limiting the
scope of the invention in any manner.
DETAILED DESCRIPTION OF THE INVENTION
Referring now to the drawings, and more particularly to Fig. 1, there is shown
an
embodiment of a centrifixgal filter assembly 10 of the present invention for
filtering
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particulates from a fluid. For example, centrifi~gal filter assembly 10 may be
used to filter
soot from engine oil in a diesel engine, and will be described accordingly.
Centrifugal filter
assembly 10 may be used for other applications, such as medical applications
for separating
particulates from a bodily or medical fluid, or machining and cutting
applications for
separating metallic particles from a hydraulic fluid or lubricating oil.
Centrifugal filter assembly 10 generally includes a housing 12, rotating
filter 14 and
turbine 16. Housing 12 contains filter 14 and defines a generally fluid-tight
vessel. For
example, housing 12 may be used as part of a bypass filter assembly for use
with an internal
combustion engine. When configured as such, a central supply tube 18 disposed
in
communication with a sump 28 extends outwardly from the engine. Housing 12
includes a
hub 20 which is rigidly attached therewith. Hub 20 includes an internal
threaded portion 22
which threadingly engages external threads on supply tube 18. Screwing hub 20
onto supply
tube 18 causes housing 12 to axially seal against the engine. An annular seal
24 on an axial
end face of housing 12 effects a fluid tight seal with the engine. Hub 20
includes external
threads 26 allowing attachment with suitable fluid conduits (not shown) for
recirculating oil
transported through filter assembly 10 back to sump 28.
Filter 14 is disposed within and rotatable relative to housing 12 about an
axis of
rotation 30 defined by supply tube 18. Filter 14 may be rotatably carried
using a pair of
reduced fi-iction bearings 32 and 34 disposed at each axial end thereof.
Bearings 32 and 34
may be, e.g., roller bearings, ball bearings or another type of reduced
friction bearing supports
such as a bushing. Filter 14 may include a suitable medium therein (not shown)
allowing
filtration of the fluid which is transported through filter 14. For example,
the medium
disposed within filter 14 may be in the form of a spiral wrapped and embossed
sheet of metal
or plastic material, as will be described in greater detail hereinafter.
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Turbine 16 is connected to filter 14 at an axial end thereof. In the
embodiment
shown, turbine 16 is attached to a bottom wall 36 of filter 14 via welding, a
suitable adhesive
or the like. The interconnection between turbine 16 and filter 14 causes
rotation of turbine 16
to in turn rotate filter 14 about axis of rotation 30.
Turbine 16 includes a plurality of blades 38 which extend generally radially
relative to
axis of rotation 30. Blades 30 may extend substantially through axis of
rotation 30, or may be
positioned at an angle offset from axis of rotation 30. Moreover, blades 38
may be
configured with a particular shape which is curved, straight, segmented, a
combination of the
same, etc., to provide a desired rotational speed of filter 14 during
operation.
Hub 20 of housing 12 includes at least one fluid port 40 defining a nozzle
through
which a pressurized fluid is jetted to impact upon turbine blades 38. In the
embodiment
shown, hub 20 includes a single fluid port 40 defining a nozzle, although a
greater number of
fluid ports may also be provided. A wall 42 disposed within hub 20 defines a
pressure
chamber 44 in communication with each of an internal bore of supply tube 18
and fluid port
40. The pressurized fluid is transported through supply tube 18 into pressure
chamber 44 and
is jetted from fluid port 40. The pressurized fluid which is jetted from fluid
port 40
sequentially impinges upon blades 38 of turbine 16. The pressurized fluid is
jetted from fluid
port 40 in a direction which is substantially perpendicular to axis of
rotation 30, thereby
eliminating force vectors in a direction parallel to axis of rotation 30 and
maximizing the
force imparted on each blade 38. The curvature and/or positioning of each
blade 38 causes a
rotational moment to be exerted on turbine 16, which in turn causes turbine 16
and filter 14 to
rotate about axis of rotation 30.
A splash shield 46 is attached to housing 12 and is disposed radially around
turbine 16
above blades 38. Pressurized fluid which is jetted radially outwardly from
fluid port 40
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against turbine blades 38 falls to a bottom of housing 12 and exits through
drain holes 48 in
hub 20. Splash shield 46 prevents an appreciable amount of pressurized fluid
from spraying
against a side wall of housing 12 and impacting against filter 14. Impact of
the pressurized
fluid would provide aerodynamic drag on filter 14 and slow the rotational
speed thereof. A
S relatively small radial clearance is provided between turbine 16 and splash
shield 46 to
minimize the amount of pressurized fluid which flows past splash shield 46 to
an area
adjacent filter 14.
Filter 14 fills with oil to be filtered during operation. One or more exit
holes 50 are
provided in the bottom side of filter 14. The size and number of holes 50, as
well as the fluid
input rate into filter 14 is a function of the desired throughput rate through
filter 14 and
residence time of the fluid within filter 14. Engine oil which drains through
holes 50 in the
bottom of filter 14 flows down the top of splash shield 46, through one or
more holes 52 in
splash shield 46, and out through drain holes 48 in hub 20.
During use, a pressurized fluid is transported from sump 28 to supply tube 18.
When
used with an internal combustion engine, the pressurized fluid may be in the
form of engine
oil which is pressurized using an oil pump to a pressure of between 30 and 70
pounds per
square inch (psi), and more particularly approximately 45 psi. Approximately
90 percent
(which actual percentage may vary) of the circulated engine oil is transported
through supply
tube 18 to pressure chamber 44 for discharging in a generally radially outward
direction
relative to axis of rotation 30 against turbine blades 38 of turbine 16. The
pressurized engine
oil causes turbine 16 to rotate at a speed of between approximately 5,000 and
20,000
revolutions per minute (RPM), more preferably between approximately 10,000 and
20,000
RPM. The remaining 10 percent of the engine oil is transported into filter 14
for centrifugal
filtration. The high rotational speed of filter 14 creates a G force which is
high enough to
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cause centrifugal separation of particulates carried within the engine oil.
The particulates
migrate radially outwardly within filter 14 and are contained within filter
14. Periodic
changing of filter 14 allows the trapped particulates within filter 14 to be
merely discarded
along with filter 14.
S Referring now to Figs. 2 and 3, there is shown another embodiment of a
centrifixgal
filter assembly 60 of the present invention. For purposes of illustration,
centrifixgal filter
assembly 60 will be described for use with an internal combustion engine, but
it is to be
understood that filter assembly 60 may be utilized for other applications.
Housing 62 is attached to an engine (not shown) utilizing flanges 64 and bolts
66. A
10 bottom cover 68 is threadingly engaged with housing 62 and is sealed with
housing 62 using
an annular O-ring 70. Bottom cover 68 may be removed from housing 62 to allow
replacement of filter 72, as will be described in greater detail hereinafter.
Turbine 74 is rotatably carned by housing 62 using one or more reduced fi-
iction
bearings, such as ball bearing assemblies 76 and 78. Turbine 74 includes a
plurality of blades
80 disposed around the periphery thereof. Blades 80 extend generally radially
relative to an
axis of rotation 82, and have a selected shape to provide a desired rotational
speed of turbine
74. The shape of blades 80 and the distance from axis of rotation 82 both have
an effect on
the rotational speed and are determined for a particular application (e.g.,
empirically).
A top cover 84 is fastened to housing 62 using, e.g., bolts 86. Seals such as
O-rings
88 provide a fluid tight seal between top cover 84 and housing 62. Top cover
84 includes
suitable porting 90 and 92 to be fluidly connected with a source of
pressurized fluid and the
fluid to be filtered, respectively. In the embodiment shown, porting 90 and 92
are each
connected with a source of pressurized engine oil which provides both the
source of
pressurized fluid for rotating turbine 74 and the fluid to be filtered.
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Nozzles 94 are attached to and carried by top cover 84, and direct a source of
pressurized fluid at selected locations against blades 80 of turbine 74. As
viewed in Fig. 2,
the left hand nozzle 94 is disposed behind central supply tube 96 and the
right hand nozzle 94
is disposed in front of supply tube 96. Nozzles 94 thus both jet a pressurized
fluid which
impinges upon blades 80 of turbine 74 on opposite sides of turbine 74. Because
nozzles 74
are carried by top cover 84 and directed generally inwardly relative to axis
of rotation 82, the
specific impingement angle of the pressurized fluid on blades 80 can easily be
adjusted for a
specific application. The angle of impingement, flow velocity of the
pressurized fluid, shape
of blades 80 and impingement location relative to axis of rotation 82 may be
configured to
provide a desired rotational speed of turbine 74
Drive nut 98 includes internal threads which are threadingly engaged with
external
threads of turbine 74. Drive nut 98 includes an upper, angled surface 100
defining a fluid
port for providing lubricating oil to bearings 76 and 78. Drive nut 98
includes a lower drive
portion 102 with a cross sectional shape which is other than circular (e.g.,
hexagonal). The
shape of lower drive portion 102 allows turbine 74 to interconnect with filter
72 and rotatably
drive filter 72 during use. A flange 104 extends from drive portion 102 and
seals with filter
72 around the outer periphery thereof with a slight compression fit.
Splash shield 106 is attached with housing 62 and directs oil away from filter
72
which is used to drive turbine 74. Splash shield 106 is press fit into housing
62 in the
embodiment shown. Pressurized fluid in the form of oil which is used to drive
turbine 74
falls via gravitational force and flows through holes 108 and into a trough
110 defined by
splash shield 106. The trough 110 is connected with an exit port (not shown)
in housing 62
for recirculating the fluid to the sump of the engine.
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Filter 72 generally includes a body 112, end cap 114 and impingement media
116.
Body 112 includes a top opening 118 which surrounds and frictionally engages
flange 104 of
drive nut 98. The press fit between flange 104 and top opening 118 is
sufficient to prevent
fluid leakage therebetween. Body 112 also includes a plurality of exit holes,
such as the two
S exit holes 120 in the top thereof. Exit holes 120 allow filtered oil to flow
therethrough and
into trough 110 during operation after filter 72 is full of the oil to be
filtered.
End cap 114 is attached with body 112 in a suitable manner. In the embodiment
shown, end cap 114 and body 112 are each formed from plastic and are
ultrasonically welded
together. However, it is also possible to attach end cap 114 with body 112 in
a different
manner, such as through a threaded or snap lock engagement. End cap 114
includes an
upwardly projecting stud 122 with an angled distal face which acts to radially
distribute oil to
be filtered which is ejected from central supply tube 96.
Impingement media 116, shown in more detail in Fig. 3, is in the form of a
long,
continuous sheet 124 of material which is wrapped in a spiral manner about
supply tube 96
1 S and stud 122. Sheet 124 is formed with a plurality of randomly located
dimples 126 which
are approximately 3/16 inch diameter and 0.070 inch deep. Each dimple 126
defines a
generally concave surface facing toward axis of rotation 82. Sheet 124 is
approximately
0.020 inch thick and includes a plurality of holes 128 between dimples 126
which have a
diameter of approximately 0.060 inch. Holes 128 are also substantially
randomly placed on
sheet 124 at locations between dimples 126 at a ratio of approximately one
hole per every six
dimples. In the embodiment shown, dimples 126 have a center-to-center distance
which
varies, but with a mean center-to-center distance of approximately 5/8 inch.
Of course, it will
be appreciated that the specific geometry and number of dimples 126 and/or
holes 128 within
sheet 124 may vary depending upon the specific application.
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Impingement media 116 in the form of a spiral wrapped sheet with dimples 126
and
holes 128 provides effective centrifugal separation of particulates within the
oil, and also
regulates the residence time of the oil within filter 72. As filter 72 rotates
at a desired
rotational speed during use, the oil to be filtered is biased radially
outwardly against an
adjacent portion of sheet 124. Particulates within the oil settle into the
concave surfaces
defined by dimples 126 and the filtered oil migrates toward a hole 128 to pass
therethrough in
a radial direction and impinge upon the next radially outward portion of sheet
124. The
radially outward flow of the oil through holes 128 in sheet 124 and trapping
of particulates
within dimples 126 continues until the filtered oil lies against the inside
diameter of body
112. An annular cap 130 at the end of spiral wrapped sheet 124 prevents the
oil from
prematurely exiting in an axial direction toward the end of filter 72. The
filtered oil flows in
an upward direction along the inside diameter of body 112 and through exit
holes 120 into
trough 110 to be transported back to the sump of the engine.
Fig. 4 illustrates yet another embodiment of a centrifugal filter assembly 140
of the
present invention. Filter assembly 140 includes a housing 142 with a filter
144 rotatably
disposed therein. Housing 142 includes an integral fluid channel 146 which
terminates at a
nozzle 148. Nozzle 148 directs pressurized fluid against turbine blades 150 of
turbine 152.
Filter 144 includes turbine 152 as an integral part thereof. That is, turbine
152 is
monolithically formed with filter 144. In the embodiment shown, filter 144 and
turbine 152
are each formed at the same time using a plastic injection molding process.
Refernng now to Fig. 5, another embodiment of a centrifugal filter assembly
160 is
shown, including a housing 142 and filter 162. Filter 162 includes a turbine
164 with a
plurality of turbine blades 168. Turbine 164 includes a deflector shield 170
attached to an
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axial end thereof which maximizes the efficiency of the pressurized fluid
jetted from nozzle
148 by confining sideways deflection of the fluid impinging on blades 168.
Fig. 6 illustrates another embodiment of a filter 174 which may be utilized
with the
centrifixgal filter assembly of the present invention. Filter 174 includes a
turbine 176 with a
plurality of variable pitch turbine blades 180. A nozzle 182 which is attached
with and
pivotable relative to a housing (not shown) about a pivot point 184 is
adjustable during use to
change the impingement angle on blades 180 and the distance from the axis of
rotation. The
composite curved shape of each blade 180 coacts with the variable impingement
angle from
nozzle 182 to vary the rotational speed of and/or torque applied to turbine
176.
Fig. 7 illustrates yet another embodiment of a centrifugal filter assembly 190
of the
present invention. Filter assembly 190 generally includes a housing 192,
filter 194 and
turbine 196. Filter 194 and turbine 196 are each disposed within housing 192
and are carried
by suitable support structure (not shown) allowing rotation around respective
axes of rotation
198 and 201. A nozzle 200 defined by housing 192 jets a flow of pressurized
fluid onto
turbine 196 to cause rotation thereof about axis of rotation 201. Rotation of
turbine 196 in
turn rotates pulley 202 which is connected via drive belt 204 with a pulley
206 rigidly
attached to filter 194. Thus, rotation of turbine 196 causes rotation of
filter 194 about axis of
rotation 198. Using an elongate force transmission element, such as drive belt
204, allows
the rotational speed of filter 194 to not only be adjusted by changing the
physical
configuration of turbine 196, but also by changing the diameters of the drive
pulley 202 and
driven pulley 206. For example, providing drive pulley 202 with a diameter
which is the
same as turbine 196 but twice as large as driven pulley 206 provides filter
194 with a
rotational speed which is twice that of turbine 196.
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Figs. 8-12 illustrate perspective views of alternative embodiments of turbines
which
may be used in a centrifugal filter assembly of the present invention. The
turbines shown in
Figs. 7-10 are fixed blade designs for use with a stationary nozzle, while the
turbine shown in
Fig. 11 is a variable geometry design for use with an adjustable nozzle.
Fig. 13 is a perspective view of yet another embodiment of a turbine 210 which
may
be utilized with a centrifugal filter assembly of the present invention.
Turbine 210 includes a
plurality of turbine blades 212 extending radially from a hub 214. A deflector
shield 216
surrounds the periphery of turbine 210 and contacts blades 212. For example,
deflector shield
216 may be press fit onto turbine 210 around the periphery of blades 212.
Deflector shield
10 216 maximizes the efl=iciency of the pressurized fluid which is jetted from
a nozzle 148 by
confining radial deflections of the fluid impinging on blades 212.
Figs. 14-16 conjunctively illustrate another embodiment of centrifugal filter
assembly
300 of the present invention, including a filter head 302, housing 304 and
rotatable filter 306.
Filter head 302 includes a body 308 with a mounting flange 310 configured for
15 connection with a source of oil to be filtered, such as an internal
combustion engine. Body
308 includes a first threaded connector 312 for connection with housing 304,
as will be
described in more detail hereinafter. An inlet 314 receives oil from the
internal combustion
engine (not shown) and an outlet 316 returns oil to the internal combustion
engine. In the
embodiment shown, inlet 314 receives engine oil from an oil gallery which is
pressurized to
the rifle pressure within the oil gallery.
A controller 318 is connected to body 308 and controls operation of a DC
brushless
motor, as will be described hereinafter. Controller 318 may include a plugable
cord 320 for
attachment with a source of direct current power, such as an electrical system
associated with
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the internal combustion engine. A heat sink 322 is attached to controller 318
for dissipating
heat to the ambient environment. Heat sink 322 may be of any suitable
configuration.
Filter head 302 also includes a brushless DC motor 324 which is carried by and
disposed within body 308. DC motor 324 includes a brushless motor coil 326, a
rotor 328
and an output shaft 330. Motor coil 326 is carried within a corresponding
recess formed in
body 308. Rotor 328 is press fit onto output shaft 330. Energization of motor
coil 326 causes
motor 328 to rotate in known manner, which in turn causes output shaft 330 to
rotate. Output
shaft 330 may be carried by a pair of reduced fi-iction bearings 332 disposed
within body 308.
Bearings 332 are located within body 308 using a bearing retainer 334 and a
snap ring 336. A
spacer 338 may be interposed between bearings 332 to maintain a proper axial
spacing
therebetween. Output shaft 330 includes a distal end defining a drive element
in the form of
a drive shaft 340 which is used to rotatably drive filter 306, as will be
described in more
detail hereinafter. Drive shaft 340 may include a drive pin 342 extending
transversely
therethrough which engages and drives filter 306.
Housing 304 is connected to filter head 302 in a suitable manner. In the
embodiment
shown, housing 304 includes a second threaded connector 344 which threadingly
engages
with first connector 312, and thereby attaches housing 304 with body 308. The
threaded
interconnection between first connector 312 and second connector 344 allows
housing 304 to
be attached with filter head 302 in a spin-on manner, thereby allowing easy
removal and
replacement of filter 306. Housing 304 may be connected to filter head 302 in
other suitable
ways, such as using a bolted flange, an annular V-shaped clamp surrounding
adjacent flanges,
an axial bolt, etc.
Housing 304 includes an open end 346, at which are disposed a pair of annular
seals
348 and 350. An annular groove 352 is disposed between first annular seal 348
and second
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annular seal 350 at open end 346. A drain tube 354 disposed within and carried
by housing
304 includes an open end which is disposed in communication with groove 352.
An opposite
open end of drain tube 354 is disposed in a bottom of housing 304. When
housing 304 is
connected with body 308, annular groove 352 is connected and disposed in
communication
with outlet 316 within body 308. Accordingly, drain tube 354 is also in
communication with
outlet 316 in body 308.
Filter 306 includes a hub 356 which engages with and is rotated by drive shaft
340. A
hub 358 disposed at an opposite end from hub 356 allows filter 306 to be
carned by a reduced
friction bearing 360 at an end opposite from drive shaft 340. Filter 306
includes a major inlet
362 which is in the form of an annular opening surrounding hub 356. Filter 306
also includes
a plurality of minor inlets 364. Each of major inlet 362 and minor inlets 364
are in
communication with and receive oil to be filtered from a feed line 366 in
filter head 302.
Feed line 366 receives pressurized oil to be filtered, as will be described in
more detail
hereinafter.
Filter 306 also includes filter media 368 disposed therein which allows soot
within the
engine oil to be effectively filtered therefrom during rotation of filter 306.
A plurality of
outlets in the form of holes 370 formed in filter 306 allow the filtered oil
to be drained from
filter 306. The filtered oil collects in a sump area 372 where it is removed
by the vacuum
pressure created within drain tube 354.
During use, pressurized oil is transported through inlet 314 in body 308 of
filter head
302. The pressurized oil flows to a venturi section 374 where the velocity of
the oil increases
and the pressure decreases. The reduced pressure caused by venturi section 374
creates a
vacuum within sump 372 and drain tube 354 which allows the filtered oil within
sump 372 to
be drawn into the area ofventuri section 374. As the oil flows past venturi
section 374, the
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pressure again increases within outlet 316 in body 308. Pressurized oil is
thus transported
through a feed line 366 to major inlet 362 and minor inlets 364 of filter 306.
The oil to be
filtered flows through filter media 368. Brushless DC motor 324 rotates drive
shaft 340 at a
known rotational speed, which in turn rotates filter 306 within housing 304.
The rotational
speed of DC motor 324 is controlled using controller 318. The rotational speed
of DC motor
324 is sufficient to filter soot from the engine oil flowing past media 368.
The filtered oil
flows through filter outlets 370 into sump 372. The filtered oil is then drawn
through drain
tube 354 to venturi section 374. The portion of the oil flowing past venturi
section 374 which
does not flow through feed line 366 instead flows in a parallel manner through
outlet 316 to
be returned to a sump in an internal combustion engine.
Referring now to Fig. 17, another embodiment of a centrifugal filter assembly
380 of
the present invention is shown. Centrifugal filter assembly 380 principally
difl~ers from
centrifugal filter assembly 300 in that rotatable drive element 382 is in the
form of a drive
cylinder driven by motor 328 of DC motor 324. Drive cylinder 382 includes a
plurality of
drive projections or tangs 384 which extend into corresponding openings 386
formed in the
top of filter 388. A stationary support shaft 390 is threadingly engaged with
filter head 302.
An opposite end of support shaft 390 is threadingly engaged with a support
shaft 392
connected with housing 394.
Fig. 18 illustrates another embodiment of a centrifugal filter assembly 400 of
the
present invention. Filter assembly 400 includes a drive cylinder 382 which
engages a filter
388, similar to the embodiment of centrifugal assembly 380 shown in Fig. 17.
However,
housing 402 is not configured as a spin-on housing as in the embodiments of
Figs. 14-16 and
17. Rather, housing 402 includes a single annular seal 404 which abuts against
filter head
406. An opposite end of housing 402 includes an opening 408 through which a
support shaft
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410 extends. A seal 412 is interposed between a head of support shaft 410 and
housing 402
to seal therebetween. Housing 402 carries a drain tube 414. However, drain
tube 414
extends past the sealing surface defined by seal 404. When housing 402 is
engaged with filter
head 406, drain tube 414 extends into a corresponding opening found in filter
head 406. An
O-ring 416 seals between drain tube 414 and filter head 406.
Fig. 19 illustrates yet another embodiment of a centrifugal filter assembly
420 of the
present invention. Filter assembly 420 includes an oil feed line 422 which
extends through
the center of drive shaft 424. Drive shaft 424 carries and rotatably drives
filter 426. Oil to be
filtered which is transported through feed line 422 impinges upon a baffle
disc 428 in the top
of filter 426. Bai~le 428 includes a plurality of inlets 430. Inlets 430 are
disposed in
communication with feed line 422, which in turn is connected with inlet 314 in
filter head
432 at the upstream side of venturi section 374. This embodiment has the
advantage of not
recycling oil which has just been filtered back to inlets 430 of filter 426.
Fig. 20 illustrates yet another embodiment of a centrifizgal filter assembly
440 of the
present invention. Filter assembly 440 includes a feed line 422 which extends
through the
center of drive shaft 424, similar to the embodiment of centrifizgal filter
assembly 420 shown
in Fig. 19. However, the oil is introduced directly into the center portion of
filter 442.
During rotation of filter 442, the oil is forced in a radially outward and
upward direction for
filtration of particulates such as soot therein. The oil then flows from a
plurality of outlets
444 formed in the top of filter 442. The oil then flows over the top of a
splash shield 446 and
flows through a plurality of openings 448 adjacent housing 450. The oil then
flows by
gravitational force to a sump 452 where it is removed via the vacuum pressure
created by
drain tube 354.
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Fig. 21 illustrates a portion of a filter head 460 which may be used in a
centrifizgal
filter assembly of the present invention. It will be appreciated that any of
the embodiments of
the centrifugal filter assembly shown in Figs. 14-20 may be adapted to utilize
filter head 460.
Filter head 460 includes a body 462 which is attached to a controller 464.
Controller 464 in
turn is attached to a heat sink 466 for dissipating heat to an ambient
environment. Controller
464 includes a printed circuit board 468 with suitable electronic circuitry
which is necessary
to control the rotational speed of a brushless DC motor including brushless
motor coil 470
and rotor 472. Controller 464 includes a radially inwardly extending
projection 474 which
supports both printed circuit board 468 and brushless motor coil 470. Motor
coil 470 and
10 printed circuit board 468 are thus connected together via radially inwardly
extending portion
474. Rotor 472 is carned by drive shaft 476, which in turn is supported by
reduced friction
bearing 478. A retainer disc 480 retains bearing 478 in place.
Fig. 22 illustrates a portion of another embodiment of a filter head 490 which
may be
used with a centrifi~gal filter assembly of the present invention. Filter head
490 includes a
15 brushless DC motor with a motor coil 492 and a rotor 494 which are disposed
adjacent to
drive shaft 496. That is, motor coil 492 and rotor 494 are interposed between
bearings 332
and drive shaft 496. A bearing retainer nut 498 retains bearings 332 in place;
and a motor
retainer disc 500 retains motor coil 492 and rotor 494 in place.
Figs. 23 and 24 illustrate fizrther embodiments of centrifugal filter
assemblies 510 and
20 512 of the present invention, respectively. Each filter assembly 510 and
512 includes a motor
514 which may be in form of a brushless DC motor, a hydraulic motor, pneumatic
motor, etc.
Likewise, each filter assembly 510 and S 12 includes a housing 516 which
rotatably supports a
filter (not shown) therein. Filter assembly 510 includes a gear train with a
plurality of gears
S 18 which are sized to provide a desired rotational speed of the filter
within housing 516.
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21
Similarly filter assembly 512 includes a plurality of pulleys 520 driven by a
common belt
522. Pulleys 520 are sized to provide a desired rotational speed of the
filters disposed within
housing 516.
Figs. 25 and 26 disclose an embodiment of an accessory power source 530 which
may
be utilized in conjunction with an accessory drive system including an
accessory drive pulley
532 of an internal combustion engine. Power source 530 includes an input
pulley 534 which
is connected via an accessory drive belt 536 with accessory drive pulley 532.
Power source
530 includes one or more output shafts 538 which may be used to drive a
centrifugal filter
assembly of the present invention. In the embodiment shown in Figs. 25 and 26,
power
source 530 includes two rotatable output shafts 538 which are respectively
oriented in a
horizontal and a vertical direction so that a selected output shaft may be
easily connected with
a centrifugal filter assembly of the present invention. Of course, power
source 530 may
include appropriate intermediate gearing therein (not shown) to adjust the
rotational output
speed of output shafts 538.
Fig. 27 illustrates yet another embodiment of a centrifugal filter assembly
540 of the
present invention. Filter assembly 540 includes a drive shaft 542 which may be
connected
with a source of power, such as a brushless DC motor. Drive shaft 542 in turn
is connected
with a disk 544 which carnes a plurality of permanent magnets 546. Disk 544 is
positioned
axially adjacent to an end 548 of a housing 550. Housing 550 rotatably carries
a filter 552
therein, such as by using bearings 554. Filter 552 also carries a plurality of
permanent
magnets 556 which are positioned adjacent to end 548 on a side opposite from
disk 544. End
548 of housing 550 is formed from a non-magnetic material so that magnetic
fields generated
by each of magnets 546 and 556 may affect each other. During use, drive shaft
542 is rotated
which in turn rotates disk 544. Rotation of permanent magnets 546 forms a
rotating
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electromagnetic field which exerts a coupling force on permanent magnets 556
carried by
filter 552. Filter 552 thus rotates within housing 550.
Fig. 28 illustrates a fi~rther embodiment of a centrifizgal filter assembly
560 of the
present invention. Centrifizgal filter assembly 560 is similar to the
embodiment of centrifugal
filter assembly 300 shown in Fig. 14. However, centrifugal filter assembly 560
includes a
gravity drain 562, rather than a venturi which siphons oil through a drain
tube.
While this invention has been described as having a preferred design, the
present
invention can be fi~rther modified within the spirit and scope of this
disclosure. This
application is therefore intended to cover any variations, uses, or
adaptations of the invention
using its general principles. Further, this application is intended to cover
such departures
from the present disclosure as come within known or customary practice in the
art to which
this invention pertains and which fall within the limits of the appended
claims.
